Communicating with an embedded system (e.g, a CPU embedded in a server) may be challenging due to the fact that embedded systems may lack a user interface, such as keyboards, monitors, or disk drives that are present on computers. Further, at least some integrated circuits (IC) include a high number of pins densely arranged to provide connection with external devices. It may be difficult to physically access external connectors of an embedded IC in view of the high pin density. Boundary scanning is a method for communicating with an embedded IC that overcomes the need to connect individual ICs.
The Joint Test Action Group (JTAG) developed a specification for boundary scan that was standardized in 1990 as the IEEE 1149.1-1990. The Boundary Scan Description Language (BSDL) describes the boundary-scan logic content of IEEE 1149.1 compliant devices. Boundary scan performed according to a IEEE standard 1149 is hereinafter referred to as JTAG boundary scan or, simply, JTAG. JTAG was originally developed to solve issues arising from the manufacturing of electronic circuits. However, JTAG is presently applied for other uses such as programming, debugging, and probing a port of an IC.
A computing system may be equipped with boundary scanning software for performing boundary scanning of an IC embedded in a target system. Such a computing system is hereinafter referred to as a boundary scanning system. An example of a boundary scanning system is a testing computer system including a module for running a diagnostics software for testing a server system, which in this example represents the target system. Such diagnostics software may operatively communicate with a JTAG bus in the target computer system by outputting testing data to a peripheral port (e.g., a USB port) connected to the JTAG bus via an interfacing peripheral (e.g., a USB-JTAG cable).
However, cable connecting the peripheral port to the JTAG bus may be inconvenient. For example, a cable connection may require opening the target computing system for accessing the JTAG bus. Further, a cable connection requires an on-site disposition of the testing computing system with respect to the target computer system. Therefore, a physical connection for performing JTAG may be cumbersome and time consuming merely by the fact that a direct physical access to the JTAG bus at the target computer system as well as co-location between the boundary scanning system and the target computing system are required.